Previously, we analyzed the expression pattern of EMT activation in a select panel of human lung cancer cells and in normal lung cells. While the EMT has been well-described in breast cancer, similar data in lung cancer and other solid tumors have been lacking. In order to better understand how the EMT and MET processes mediate cancer cell metastasis in lung cancer, we have recently developed a laboratory animal model of lung cancer metastasis to better understand the developement and progression of cancer. In particular, we have been studying lung cancer cells metastasizing to the brain in these models, seeking to identify critical factors which predispose particular cancer cells to migrate and colonize distantly. These models will allow us to better dissect out and identify key modulators of the metastasis process in order to discover new potential targets for therapy.